Fertile land the size of France has been damaged by salt, a new Manhattan weekly

An additional area the size of Manhattan is lost every week

Feeding billions of people is putting a lot of pressure on arable land, and with population growth, that's only going to increase (with 9 billion people by 2050, we would need 70 percent more food). So the last thing we need is to be losing thousands of hectares of fertile land to salt damage every day. A new U.N. report shows that about 5,000 acres (2,000 hectares) of fertile land have been lost each day for the past 20 years due to damage caused by salt, with an area affected equivalent to the size of France (62 million hectares). This is an increase from an already alarming 45 million hectares of damaged fertile land 20 years ago.

We have to wake up. Each week, the world loses an area larger than Manhattan to salt degradation.

Apple Maps/Screen capture

20% of all irrigated lands

What is the problem exactly? The U.N. explains: "Salt-induced land degradation occurs in arid and semi-arid regions where rainfall is too low to maintain regular percolation of rainwater through the soil and where irrigation is practiced without a natural or artificial drainage system. Irrigation practices without drainage management trigger the accumulation of salts in the root zone, affecting several soil properties and reducing productivity."

$27 billion+ in lost crop value per year

The environmental cost itself is gigantic, but there's also a great economic cost. The U.N. estimates that the inflation-adjusted cost of salt land degradation last year was about US$441 per hectare, which represents a cumulative loss of US$27.3 billion per year.

Thankfully, there are ways to restore the damaged land, and it would cost a lot less than $30 billion per year:

Methods successfully used to facilitate drainage and reverse soil degradation include tree planting, deep plowing, cultivation of salt-tolerant varieties of crops, mixing harvested plant residues into topsoil, and digging a drain or deep ditch around the salt-affected land.

Reversing land degradation and bringing salt-affected lands back into a highly productive state are expected to result in favorable environmental benefits in addition to economic gains, although functional markets for many of the ecosystem services are currently embryonic or nonexistent.

Planting trees, etc. We're not talking about rocket science, and the side benefits of doing this would extend beyond just agriculture.